1. Field of the Invention
The invention relates to a method of producing a semiconductor wafer in which grease components and abrasive grains are removed away from a semiconductor wafer cut by a wire saw and the semiconductor wafer is separated from a carbon slicing plate, thereby obtaining a sliced wafer, and also to a cleaning apparatus for the method.
2. Prior Art
Recently, a wire saw is rapidly becoming widespread in the process of cutting a semiconductor ingot of a larger diameter such as 8 inches or 12 inches. Semiconductor wafers which have been cut by a wire saw are cleaned while the wafers are arranged in a row and peripheral portions of the wafers are bonded to a slicing plate made of carbon, thereby removing away grease components and abrasive grains which have adhered to the semiconductor wafers during the cutting process.
Conventionally, the cleaning work is conducted while using a single cleaning bath and replacing cleaning fluids with one other, or while moving among plural cleaning baths. The replacing or moving work must be manually conducted.
In order to separate the semiconductor wafers from the slicing plate, the semiconductor wafers which have been rinse-cleaned are immersed together with the slicing plate into, for example, an alkaline detergent containing 3.0% or more of an anionic surface active agent, thereby conducting a separating work.
The works which are manually conducted have problems in that they are low in efficiency, and that the human body may be adversely affected by chemical fluids and the like.
Abrasive grains which are on the surface of each semiconductor wafer are removed away as a result of the cleaning steps previous to and including the rinse-cleaning step. However, abrasive grains entering strain layers produced in the cutting work cannot be removed away. When the semiconductor wafers are separated from the slicing plate without subjecting the wafers to a further process, there arises a problem in that the abrasive grains in strain layers are brought into the subsequent step.